Muni Onaruto is a first-year student at Yoba Academy and a core member of the DJ unit Happy Around!, serving as the group's visual jockey and a vocalist. Her background is rooted in a childhood encounter with Rinku Aimoto, who praised her drawings, inspiring Muni to take art seriously. This encouragement led her to become a well-known illustrator online. In terms of personality, Muni often appears blunt or rude, but this behavior arises from social awkwardness and deep self-consciousness. She has a strong affinity for cute things, consumes almost exclusively junk food, and carries a cat-shaped MP3 player named Nyochio. She frequently refers to herself as the one and only Muni-chan. Muni is highly proficient with technology, including computers, gaming, and social media, and is rarely without a tablet or laptop. Her primary motivation is a desire for praise and acceptance, a need that traces back to Rinku’s early encouragement. Within the story of D4DJ Double Mix and the broader D4DJ series, Muni handles the visual elements of Happy Around!'s performances, crafting dynamic graphics and videos that complement the unit's energetic music. Key relationships include a deep but sometimes complicated bond with Rinku; Muni has experienced jealousy when Rinku focuses on others and once distanced herself out of fear of being left behind. She works closely with Maho Akashi and Rei Togetsu, her role often balancing her guarded nature with the group's collective drive. Her character development involves gradually opening up, overcoming her insecurities, and learning to trust her friends while reconciling her need for validation with her own sense of self-worth. Notable abilities include her talent as a graphic designer and illustrator, her technical skill as a VJ, advanced computer literacy, and a knack for creating engaging social media content. She also brings a playful, inventive energy to the unit through her use of Nyochio and her unique catchphrase.